<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>用户注册</title>
</head>
<body>
<form action="RegisterServlet" method="post">
用户名：<input name="username" type="text">
年龄：<input name="age"><br>
性别：<input type="radio" name="sex" value="男" />男<input type="radio" name="sex" value="女" />女<br>
Email：<input type="text" name="email" value="电子邮件" onfocus="this.value = '';" onblur="if (this.value == '') {this.value = '请输入电子邮件;}">
<input type="submit">
</form>
</body>
</html>